[isabelle-dev] Isabelle website

Gottfried Barrow gottfried.barrow at gmx.com
Mon Sep 30 16:12:14 CEST 2013

On 9/30/2013 6:10 AM, Makarius wrote:
> There could be some nice videos instead, but I still don't know how to 
> produce them.

The most popular screen-capture software for instructional videos is 

1) http://www.techsmith.com/camtasia.html
2) Docs: http://www.techsmith.com/tutorial-camtasia-8.html
3) Trial: http://www.techsmith.com/download/camtasia/
4) Search on "TechSmith Camtasia Studio dizel_ avaxhome" if you need 
more than 30 days to decide whether it's the way you want to go.

The hard part is the learning curve for Camtasia, and creating your 
standard 5 second lead-in for the videos. Other than that, it should be 
easy, not that I've done it yet:

1) Make sure you get clean, hot audio from your microphone, but not 
distorted. Recording at 44.1 mono at 128kbps mpg3 is good.
2) Capture to a wide-screen format like 800x450, 960x540, 1024x576, or 
1280x720. Find a happy medium between clear video without bad 
compression artifacts, and decent file size. Mpeg4 will give you good 
quality for 1280x720 and only take 10 Mbytes/minute. Camtasia has it's 
own encoders, and I don't know the settings yet that you need to get 
good quality with reasonable file size.
3) Capture your video: record and talk while you're doing screen 
capture, and hit the pause button if you need to think.
4) Edit the video: fade in with a 3-5 second lead-in with a professional 
looking graphic, the title of your specific video, and an optional music 
or sound effects clip.
5) Edit out long pauses and less desirable dialog, which is as simple as 
dragging a vertical bar to the left.
6) Fade out at the end, or fade out with a graphic, or fade out with a 
graphic and a music clip.
7) Render it to a good format like mpeg4 and put it up on Youtube.

HINT: There are codecs such as MP4 and H.264, and then there are codec 
container files, like MP4 and AVI. It all gets confusing, and I only 
know the minimum, but the MP4 codec can be contained in both a MP4  and 
AVI file. An important thing I've learned is that you can't get much 
better than MP4 at getting both good quality and small file size. Other 
codecs, however, do get much worse. The licensing of MP4 prevents it 
from being freely used in video software, so won't find much free 
editing software that uses it.


EXAMPLE: Lead-in with graphic, music, and title, and then he just talks 
with screen capture, with simple cut edits. The audio has too much room 
reverb in it because his microphone is not close enough, but it's an 
example of a site that is constantly putting out new videos, with the 
main emphasis on instruction, rather than flashy video effects:


EXAMPLE: Lead-in with graphic, title, and no music, and then he just 
talks with screen capture, with simple transitions for the cuts:


EXAMPLE: Camtasia tutorial with simple title lead-in, with transitions 
for the cuts, but you don't really need the transistions

If you want to get fancy, you can add 3 seconds of sound effects and 
some dramatic audio to your lead in:


Or you can search on the web for some free audio clips.

The examples are just to show that after you learn how to use the 
software, you just talk while doing screen capture, and then you cut out 
what you say that doesn't flow good. It's like with lots of software 
applications, after your initial investment of time to get a template, 
it can be less trouble to do it all yourself than to part of it 
yourself, and have someone else do the rest.

The big differences between a reasonably-professional video and 
total-amateur are good audio, good video quality, cutting out 
undesirable dialog, a lead in, and a lead out. For instructional videos 
about software, anything other than simple cut edits between the 
beginning and end of the video is not necessary. You'd do fancier 
effects and transitions if you found time and were inclined to do it.

The hard part is learning the software, creating your lead in, and 
experimenting with codecs to get good video quality with reasonable file 
size. Camtasia might make the codec part easy, but I don't know. If all 
I was wanting to do is what I've explained, life would be easy.


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